CB26 - Heating and Air Parts

Service Literature 

Corp. 0527−L10 

Revised May 2011 

CB26UH and CBX26UH Series 

Table of Contents 

CB26UH 

CBX26UH 

Model Number Information . . . . . . . . . . . . . . . . . . . 2 

Specifications / Electrical Data . . . . . . . . . . . . . . . . 3 

Blower Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

I Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

II Unit Components . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

III Optional Electric Heat . . . . . . . . . . . . . . . . . . . . 10 

IV Configuration Modification . . . . . . . . . . . . . . . . 16 

V Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 

VI Typical Operating Characteristics . . . . . . . . . . 19 

WARNING 

Improper installation, adjustment, alteration, service 

or maintenance can cause personal injury, loss of 

life, or damage to property. 

Installation and service must be performed by a 

licensed professional installer (or equivalent) or a 

service agency. 

CAUTION 

Physical contact with metal edges and corners while 

applying excessive force or rapid motion can result 

in personal injury. Be aware of, and use caution when 

working near these areas during installation or while 

servicing this equipment. 

IMPORTANT 

The Clean Air Act of 1990 bans the intentional venting 

of refrigerant (CFCs, HCFCs and HFCs) as of July 1, 

1992. Approved methods of recovery, recycling or 

reclaiming must be followed. Fines and/or 

incarceration may be levied for noncompliance. 

VII Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 

VIII Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . 20 

The CB26UH, and CBX26UH are high efficiency blower coils. 

Several models are available in sizes ranging from 1-1/2 

through 5 tons (5.3 through 17.6 kW). The CBX26UH is 

designed for HFC−410A refrigerant and the CB26UH is 

designed for HCFC−22 refrigerant. The units are up flow / 

horizontal that can be field converted to down flow applications. 

The units come with a factory installed check and expansion 

valve for cooling or heat pump applications. 

CB26UH and CBX26UH series units are designed to be 

matched with the 13SEER air conditioner and heat pump line, 

but can be matched with other air conditioners or heat pumps 

as noted in the rating information. See Engineering Handbook. 

Electric heat, in several kW sizes, can be field installed in the 

CB26UH and CBX26UH cabinets. 

Information contained in this manual is intended for use by 

experienced HVAC service technicians only. All specifications 

are subject to change. Procedures outlined in this manual are 

presented as a recommendation only and do not supersede or 

replace local or state codes. 

Page 1 

2011 Lennox Industries Inc. 

Litho U.S.A.

MODEL NUMBER IDENTIFICATION 

Unit Type 

CB = Air Handler 

Series 

Configuration 

UH = Up−Flow / Horizontal 

MODEL NUMBER IDENTIFICATION 

CB 26 UH − 030 − R − 230 − 1 

Metering Device 

R = Factory Installed RFCIV 

(No R = TXV) 

Nominal Cooling Capacity 

018 = 1.5 tons 042 = 3.5 tons 

024 = 2 tons 

048 = 4 tons 

030 = 2.5 tons 060 = 5 tons 

036 = 3 tons 

CB X 26 UH − 030 − 230 − 1 

Minor Revision Number 

Voltage 

230 = 208/230V−1phase−60hz 

Unit Type 

CB − Air Handler 

Refrigerant Type 

X = HFC−410A 

Series 

Configuration 

UH = Up−Flow / Horizontal 

Nominal Cooling Capacity 

018 = 1.5 tons 

024 = 2 tons 

030 = 2.5 tons 

036 = 3 tons 

037 = 3 tons 

042 = 3.5 tons 

048 = 4 tons 

060 = 5 tons 

Minor Revision Number 

Voltage 

230 = 208/230V−1 phase−60hz 

Page 2

SPECIFICATIONS — CB(X)26UH−0XX−(R)−230−01 Build 

General 

Data 

Model Number CBX26UH−018 CBX26UH−024 CBX26UH−030 CBX26UH−036 

Nominal tonnage 1.5 2 2.5 3 

Connections Suction/Vapor line (o.d.) − in. (mm) sweat 3/4 (19) 3/4 (19) 7/8 (22.2) 7/8 (22.2) 

Liquid line (o.d.) − in. (mm) sweat 3/8 (9.5) 3/8 (9.5) 3/8 (9.5) 3/8 (9.5) 

Condensate − in. (mm) fpt (2) 3/4 (19) (2) 3/4 (19) (2) 3/4 (19) (2) 3/4 (19) 

Indoor 

Coil 

Net face area − ft. 2 (m 2 ) 4 (0.37) 4 (0.37) 4.88 (0.45) 4.88 (0.45) 

Tube outside diameter − in. (mm) 3/8 (9.5) 3/8 (9.5) 3/8 (9.5) 3/8 (9.5) 

Number of rows 3 3 3 3 

Fins per inch (fins per m) 15 (591) 14 (551) 14 (551) 14 (551) 

Blower Wheel nominal diameter x width − in. (mm) 10 x 6 

(254 x 152) 

1 Filters Size of filter − in. (mm) 15 x 20 x 1 

(406 x 508 x 25) 

ELECTRICAL DATA 

10 x 6 

(254 x 152) 

11 x 8 

(279 x 203) 

11 x 8 

(279 x 203) 

Blower motor output − hp (W) 1/4 (187) 1/4 (187) 1/4 (187) 1/3 (249) 

15 x 20 x 1 18 x 20 x 1 

(406 x 508 x 25) (457 x 508 x 25) 

18 x 20 x 1 

(457 x 508 x 25) 

Voltage − 1 phase (60 hz) 208/240V 208/240V 208/240V 208/240V 

2 Maximum overcurrent protection (unit only) 15 15 15 15 

3 Minimum circuit ampacity (unit only) 1.5 1.5 1.6 2.0 

Shipping Data −1 package − lbs. (kg) 129 (58) 131 (59) 148 (67) 148 (67) 

SPECIFICATIONS — CB(X)26UH−0XX−(R)−230−01 Build 

General 

Data 

Model Number CBX26UH−037 CBX26UH−042 CBX26UH−048 CBX26UH−060 

Nominal tonnage 3 3.5 4 5 

Connections Suction/Vapor line (o.d.) − in. (mm) sweat 7/8 (22.2) 7/8 (22.2) 7/8 (22.2) 7/8 (22.2) 

Liquid line (o.d.) − in. (mm) sweat 3/8 (9.5) 3/8 (9.5) 3/8 (9.5) 3/8 (9.5) 

Condensate − in. (mm) fpt (2) 3/4 (19) (2) 3/4 (19) (2) 3/4 (19) (2) 3/4 (19) 

Indoor 

Coil 

Net face area − ft. 2 (m 2 ) 5.84 (0.54) 5.84 (0.54) 7.58 (0.70) 8.76 (0.81) 

Tube outside diameter − in. (mm) 3/8 (9.5) 3/8 (9.5) 3/8 (9.5) 3/8 (9.5) 

Number of rows 3 3 3 3 

Fins per inch (fins per m) 14 (551) 14 (551) 14 (551) 14 (551) 


(279 x 203) 

11 x 8 

(279 x 203) 

11 x 8 

(279 x 203) 

11−1/2 x 9 

(292 x 229) 

Blower motor output − hp (W) 1/3 (249) 1/3 (249) 1/2 (373) 1/2 (373) 


(457 x 635 x 25) 

18 x 25 x 1 

(457 x 635 x 25) 

18 x 25 x 1 

(457 x 635 x 25) 

18 x 25 x 1 

(457 x 635 x 25) 


Voltage − 1 phase (60 hz) 208/240V 208/240V 208/240V 208/240V 

2 Maximum overcurrent protection (unit only) 15 15 15 15 

3 Minimum circuit ampacity (unit only) 1.8 2.0 2.6 4.1 

Shipping Data −1 package − lbs. (kg) 172 (78) 172 (78) 177 (80) 190 (86) 

1 Filter is not furnished and must be field supplied. 

2 HACR type circuit breaker or fuse. 

3 Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements. Use wires suitable for at least 167F (75C). 

Page 3

SPECIFICATIONS — CB(X)26UH−0XX−(R)−230−02 Build 4 

General 

Data 

Model Number CBX26UH−042 CBX26UH−048 CBX26UH−060 

Nominal tonnage 3.5 4 5 

Connections Suction/Vapor line (o.d.) − in. (mm) sweat 7/8 (22.2) 7/8 (22.2) 7/8 (22.2) 

Liquid line (o.d.) − in. (mm) sweat 3/8 (9.5) 3/8 (9.5) 3/8 (9.5) 

Condensate − in. (mm) fpt (2) 3/4 (19) (2) 3/4 (19) (2) 3/4 (19) 

Indoor 

Coil 

Net face area − ft. 2 (m 2 ) 5.84 (0.54) 7.58 (0.70) 8.76 (0.81) 

Tube outside diameter − in. (mm) 3/8 (9.5) 3/8 (9.5) 3/8 (9.5) 

Number of rows 3 3 3 

Fins per inch (fins per m) 14 (551) 14 (551) 14 (551) 


(279 x 203) 

11−1/2 x 9 

(279 x 203) 

12 x 9 

(292 x 229) 

Blower motor output − hp (W) 1/2 (373) 1/2 (373) 1/2 (373) 


(457 x 635 x 25) 

18 x 25 x 1 

(457 x 635 x 25) 

18 x 25 x 1 

(457 x 635 x 25) 

Shipping Data −1 package − lbs. (kg) 172 (78) 177 (80) 190 (86) 


Voltage − 1 phase (60 hz) 208/240V 208/240V 208/240V 

2 Maximum overcurrent protection (unit only) 15 15 15 

3 Minimum circuit ampacity (unit only) 2.0 2.6 4.1 

1 Filter is not furnished and must be field supplied. 

2 HACR type circuit breaker or fuse. 

3 Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements. Use wires suitable for at least 167F (75C). 

4 Only the 3.5, 4 and 5 ton units had specifications changed for −02 build. Use previous specification section for all other sizes. 

Page 4

BLOWER DATA 

The following tables pertain to the −01 build CB(X)26UH−0XX−230−01: 

CB(X)26UH−018−230−01 BLOWER PERFORMANCE 

Air Volume at 

External Static 

Specific Blower Taps 

Pressure 

High 

Low 

in. w.g. Pa cfm L/s cfm L/s 

.10 25 1020 460 755 340 

.20 50 960 435 715 325 

.30 75 885 400 675 305 

.40 100 800 365 625 285 

.50 125 690 315 570 260 

.60 150 525 250 500 235 

NOTE − All air data measured external to unit with dry coil and 1 inch non−pleated air 

filter in place. Electric heaters have no appreciable air resistance. 





Pressure 

High 

Low 


.10 25 1350 610 1145 520 

.20 50 1290 585 1090 495 

.30 75 1225 555 1030 465 

.40 100 1150 520 960 435 

.50 125 1065 485 875 395 

.60 125 965 455 775 365 







Pressure 

High 

Low 


.10 25 1940 880 1785 810 

.20 50 1845 835 1705 775 

.30 75 1745 790 1615 730 

.40 100 1630 740 1515 685 

.50 125 1495 680 1400 635 

.60 150 1330 630 1265 595 







Pressure 

High 

Low 


.10 25 2160 980 2075 940 

.20 50 2065 935 1985 900 

.30 75 1960 890 1885 855 

.40 100 1845 835 1775 805 

.50 125 1710 775 1645 745 

.60 150 1550 730 1495 705 







Pressure 

High 

Low 


.10 25 1040 470 1000 455 

.20 50 980 445 940 425 

.30 75 905 410 870 395 

.40 100 815 370 785 355 

.50 125 705 320 680 310 

.60 150 535 250 530 250 







Pressure 

High 

Low 


.10 25 1560 705 1405 635 

.20 50 1480 670 1340 610 

.30 75 1390 630 1270 575 

.40 100 1290 585 1185 540 

.50 125 1170 530 1090 495 

.60 150 1015 480 975 460 







Pressure 

High 

Low 


.10 25 1945 880 1870 850 

.20 50 1860 845 1790 810 

.30 75 1765 800 1700 770 

.40 100 1660 155 1600 725 

.50 125 1540 700 1485 675 

.60 150 1395 660 1350 635 



Page 5

The following tables pertain to the −01 build CB(X)26UH−0XX−(R)−230−01 Applicable to units with a three speed motor with 

date of manufacture date code of January 2009 through January 2010: 

NOTE − All air data measured external to unit with dry coil and 1 inch non−pleated air filter in place. Electric heaters have no appreciable air resistance. 

CBX26UH−018 BLOWER PERFORMANCE 


Pressure 



High Medium Low 

in. w.g. Pa cfm L/s cfm L/s cfm L/s 

0.10 25 1035 490 995 470 720 340 

0.20 50 960 450 925 435 700 330 

0.30 75 875 410 840 395 655 310 

0.40 100 780 370 705 335 610 285 

0.50 125 665 315 625 295 515 245 





Pressure 





0.10 25 1290 610 1060 500 930 440 

0.20 50 1270 600 1045 490 915 430 

0.30 75 1215 570 1015 480 890 420 

0.40 100 1155 545 950 445 840 395 

0.50 125 1045 490 840 395 735 350 





Pressure 





.10 25 1625 765 1460 690 1220 575 

.20 50 1610 760 1450 685 1215 575 

.30 75 1565 740 1440 680 1200 566 

.40 100 1540 725 1405 665 1165 550 

.50 125 1440 680 1320 625 1095 515 

.60 150 1385 655 1205 570 1022 480 





Pressure 





0.10 25 1885 890 1760 830 1595 750 

0.20 50 1820 860 1710 805 1580 745 

0.30 75 1740 820 1635 770 1525 720 

0.40 100 1605 755 1540 725 1445 680 

0.50 125 1445 680 1395 660 1320 620 





Pressure 





0.10 25 1035 490 995 470 720 340 

0.20 50 960 450 925 435 700 330 

0.30 75 875 410 840 395 655 310 

0.40 100 780 370 705 335 610 285 

0.50 125 665 315 625 295 515 245 





Pressure 





0.10 25 1495 705 1355 640 1135 535 

0.20 50 1470 695 1345 635 1120 530 

0.30 75 1415 670 1315 620 1110 525 

0.40 100 1335 630 1260 595 1080 510 

0.50 125 1250 590 1090 515 995 470 





Pressure 





0.10 25 1540 725 1405 665 1200 565 

0.20 50 1530 720 1415 665 1190 565 

0.30 75 1505 710 1385 655 1160 545 

0.40 100 1385 655 1305 615 1115 525 

0.50 125 1255 590 1190 565 1000 470 





Pressure 





0.10 25 2110 995 2065 975 1780 840 

0.20 50 2065 975 1960 925 1755 830 

0.30 75 1950 920 1860 880 1670 790 

0.40 100 1770 835 1715 810 1555 735 

0.50 125 1585 750 1475 695 1395 655 



Page 6

The following tables pertain to the −02 build CB(X)26UH−0XX−(R)−230−02: 

Only the 3.5, 4 and 5 ton units had CFM specifications changed for −02 build. Use previous section CFM tables for all other 

sizes. 

NOTE − All air data measured external to unit with dry coil and 1 inch non−pleated air filter in place. Electric heaters have no appreciable air resistance. 


External 

Static 

Pressure 

Air Volume at Specific Blower Taps 


w.g Pa cfm L/s cfm L/s cfm L/s 

0.10 25 1803 851 1707 806 1603 757 

0.20 50 1749 825 1635 772 1542 728 

0.30 75 1665 786 1561 737 1474 696 

0.35 87 1614 762 1530 722 1449 684 

0.40 100 1545 729 1482 699 1407 664 

0.45 112 1474 696 1416 668 1373 648 

0.50 125 1416 668 1373 648 1301 614 

0.55 137 1373 648 1292 610 1254 592 


External 

Static 

Pressure 




0.10 25 2276 1074 2080 982 1734 818 

0.20 50 2184 1030 2038 962 1712 808 

0.30 75 2092 987 1971 930 1688 797 

0.35 87 2020 953 1920 906 1673 790 

0.40 100 1958 924 1855 875 1644 776 

0.45 112 1881 888 1801 850 1567 740 

0.50 125 1842 869 1717 810 1503 709 

0.55 137 1675 791 1583 747 1418 669 


External 

Static 

Pressure 




0.10 25 2181 1029 2158 1018 1743 823 

0.20 50 2112 997 1943 917 1700 802 

0.30 75 1918 905 1826 862 1641 774 

0.35 87 1839 868 1771 836 1596 753 

0.40 100 1771 836 1700 802 1565 739 

0.45 112 1700 802 1657 782 1517 716 

0.50 125 1642 775 1581 746 1451 685 

0.55 137 1549 731 1517 716 1399 660 

Page 7

CB26UH AND CBX26UH PARTS ARRANGEMENT 

ELECTRIC HEAT SECTION 

(plate to be removed if installed) 

BLOWER COMPARTMENT 

CONTROL BOX 

COIL 

HORIZONTAL DRAIN PAN 

EXPANSION VALVE 

(R−22 or R−410A) 

UP−FLOW DRAIN PAN 

FIGURE 1 

Page 8

I−APPLICATION 

CAUTION 

Electrostatic discharge can affect electronic 

components. Take precautions during unit installation 

and service to protect the unit’s electronic 

controls. Precautions will help to avoid control 

exposure to electrostatic discharge by putting 

the unit, the control and the technician at the 

same electrostatic potential. Neutralize electrostatic 

charge by touching hand and all tools on an 

unpainted unit surface before performing any 

service procedure. 

All major blower coil components must be matched 

according to Lennox recommendations for the unit to be 

covered under warranty. Refer to the Engineering Handbook 

for approved system matchups. A misapplied system will 

cause erratic operation and can result in early unit failure. The 

units come with factory installed check and expansion valve for 

all applications. The TXV valve has been installed internally for 

a cleaner installation and is accessible if required. 

II−UNIT COMPONENTS 

A−Control Box 

The CB26UH and CBX26UH control box is located above 

the blower section shown in figure 1. Line voltage and 

electric heat connections are made in the control box. 

Optional electric heat fits through an opening located in the 

center of the control box. When electric heat is not used, 

cover plates cover the opening. The electric heat control 

arrangement is detailed in the electric heat section of this 

manual. 

1−Transformer 

All CB26UH and CBX26UH series units use a single line 

voltage to 24VAC transformer mounted in the control 

box. The transformer supplies power to the control 

circuits in the indoor and outdoor unit. Transformers are 

rated at 40VA. 208/240VAC single phase transformers use 

two primary voltage taps as shown in figure 2. 

208 / 240 VOLT TRANSFORMER 

240 VOLTS 

PRIMARY 

ORANGE 

RED 

208 VOLTS 

BLACK 

FIGURE 2 

BLUE 

YELLOW 

SECONDARY 

2−Blower Relay 

All CB26UH and CBX26UH units use a double−pole 

single−throw (DPST) switch relay to energize the blower 

motor. The relay coil is energized by blower demand 

from indoor thermostat. When the coil is energized, a set of 

normally open (N.O.) contacts closes to energize the blower 

motor on cooling speed. When de−energized, a set of normally 

closed (N.C.) contacts allows the electric heat relay to energize 

the blower on heating speed (refer to unit wiring diagram). 

3−Time Delay Relay 

The blower time delay is a 24 volt N.O. relay wired to the 

blower relay. See unit diagram. The delay is between 10 

and 60 seconds and delays the blower on and off time in the 

cooling cycle. 

BLOWER ASSEMBLY 

B−Blower Motor (B3) 

FIGURE 3 

CB26UH and CBX26UH units use single phase direct drive 

blower motors with a run capacitor. Figure 3 shows the 

parts arrangement. All motors have two speed taps. 

Typically, the high speed tap is energized during normal 

operation. 

All units are factory wired for the high blower speed for heat 

pump and cooling applications with or without electric heat. No 

field wiring is required. The wiring diagrams show factory set 

blower speeds. 

1−Blower Motor Capacitor 

All CB26UH and CBX26UH series units use single phase 

direct drive motors with a run capacitor. The run capacitor is 

mounted on the blower housing. See figure 3. Capacitor 

ratings are shown on side of capacitor and indoor blower motor 

nameplate. 

Page 9

C−Coil 

CB26UH and CBX26UH units have dual slab coils 

arranged in an A configuration. Each coil has two or three 

rows of copper tubes fitted with ripple−edged aluminum 

fins. An expansion valve, feeds multiple parallel circuits through 

the coils. The coil is designed to easily slide out of the unit 

cabinet. 

D−Plastic Drain Pans 

Drain pans are provided and installed on the CB26UH and 

CBX26UH, The drain pans are made from fiberglass filled 

plastic. 

III−OPTIONAL ECB26 ELECTRIC HEAT 

A−Matchups and Ratings 

Tables 2 through 5 show all approved CB26UH and 

CBX26UH to ECB26 matchups and electrical ratings. 

B−Electric Heat Components 

ECB26 parts arrangement is shown in figure 4. All electric heat 

sections consist of components mounted to the electric heat 

vestibule panel and electric heating elements exposed directly 

to the airstream. 208/230V electric heat sections may be 

equipped with circuit breakers. The circuit breakers are 

designated by CB in the model number. 

1 − Electric Heat Sequencer Relays 1 and 2 

Relays are N.O. sequencer relays with a resistive 

element for a coil and a bi-metal disk which actuates 

the contacts. The relays are located on the electric heat 

vestibule panel and are energized by a 24V heating 

demand (W1 and W2) via jack/plug 2. When energized, 

the internal resistance heats the bi-metal disk causing the 

contacts to close. When the relay is de-energized, the 

disk cools and the contacts open. The relays 

energize different stages of heat, as well as the 

blower. The blower is always first on and last off. 

2 − Primary Limits 1, 2, 3 & 4 

The primary limits are located on the electric heat vestibule 

panel and exposed directly to the airstream through an 

opening in the panel. They are SPST N.C. auto −reset 

limits. The limits are factory set and not adjustable. 

208/230 Volt Electric Heat Sections 

Each stage of the 208/230 electric heat is protected 

by a primary high temperature limit. Each stage uses the 

same style of limit. The primary limit is wired in series with 

a heat element. When either limit opens, the 

corresponding heat element is de-energized. All 

other heating elements remain energized. The primary 

high temperature limit opens at 150F + 5F (65.5C + 

2.8C) on a temperature rise and automatically resets 

at 110F + 9F (43.3C + 5.0C) on a temperature 

fall. 

3 − Circuit Breaker 

Line voltage connections are made to circuit breakers in 

the electric heat sections with circuit breakers (designated 

by CB in the model numbers). Table 1 shows the amp 

rating for each circuit breaker used. Single phase electric 

heat uses two pole circuit breakers. 

TABLE 1 

ECB29 CIRCUIT BREAKERS 

UNIT CB1 AMPS CB2 AMPS CB3 AMPS 

ECB26-5CB-1 (P) 30 AMP −−− −−− 

ECB26-7CB-1 (P) 45 AMP −−− −−− 

ECB2610CB-1 (P) 60 AMP −−− −−− 

ECB26-15CB-1 (P) 60 AMP 30 AMP −−− 

ECB26-20CB-1 (P) 60 AMP 60 AMP −−− 

4 − Heating Elements 

Heating elements are composed of helix wound bare 

nichrome wire exposed directly to the airstream. The 

elements are supported by insulators mounted to the 

wire frame. For single phase applications, one 

element is used per stage. Each stage is energized 

independently by the corresponding relay located 

on the electric heat vestibule panel. Once 

energized, heat transfer is instantaneous. High 

temperature protection is provided by primary high 

temperature limits. 

ECB26−7, -7CB, -10, -10CB 208/230 

VESTIBULE PARTS ARRANGEMENT 

ELECTRIC HEAT 

SEQUENCER 

1 & 2 

CIRCUIT BREAKER 

FIGURE 4 

HEATING ELEMENTS 

PRIMARY LIMITS 

1, 2, 3 & 4 

Page 10

SINGLE PHASE 

2.5 kW ECB26−2.5 (19W05) 

Terminal Block 

5 kW ECB26−5 (99M64) 


ECB26−5CB (99M65) 

Circuit Breaker 

7.5 kW ECB26−7 (99M67) 








TABLE 2 

Description Input Blower 

Motor 

Full Load 

Amps 

CB(X)26UH−018 / CBX26UH−024 

2 Minimum 

Circuit 

Ampacity 

3 Maximum 

Overcurrent 

Protection 

Volt kW 1 Btuh Ckt 1 Ckt 2 Ckt 1 Ckt 2 2 Minimum 

Circuit 

Ampacity 

Single Point 

Power Source 

3 Maximum 

Overcurrent 

Protection 

208 1.9 6,400 1.5 13.3 − − − 15 − − − − − − − − − 

220 2.1 7,200 1.4 13.7 − − − 15 − − − − − − − − − 

230 2.3 7,800 1.4 14.3 − − − 15 − − − − − − − − − 

240 2.5 8,500 1.4 14.8 − − − 15 − − − − − − − − − 

208 3.8 12,800 1.5 24.7 − − − 4 25 − − − − − − − − − 

220 4.2 14,300 1.4 25.6 − − − 30 − − − − − − − − − 

230 4.6 15,700 1.4 26.8 − − − 30 − − − − − − − − − 

240 5.0 17,100 1.4 27.8 − − − 30 − − − − − − − − − 

208 5.6 19,200 1.5 35.5 − − − 4 40 − − − − − − − − − 

220 6.3 21,500 1.4 37.5 − − − 4 40 − − − − − − − − − 

230 6.9 23,500 1.4 39.3 − − − 4 40 − − − − − − − − − 

240 7.5 25,600 1.4 40.8 − − − 45 − − − − − − − − − 

208 7.5 25,600 1.5 46.9 − − − 4 50 − − − − − − − − − 

220 8.4 28,700 1.4 49.5 − − − 4 50 − − − − − − − − − 

230 9.2 31,400 1.4 51.8 − − − 60 − − − − − − − − − 

240 10.0 34,100 1.4 53.8 − − − 60 − − − − − − − − − 

NOTE − Circuit 1 Minimum Circuit Ampacity includes the Blower Motor Full Load Amps. 

1 Electric heater capacity only − does not include additional blower motor heat capacity. 

2 Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements. Use wires suitable for at least 167F. 

3 HACR type breaker or fuse. 

4 Bold indicates that the circuit breaker on CB" circuit breaker models must be replaced with size shown. 

Page 11

SINGLE PHASE 















12.5 kW ECB26−12.5CB (19W00) 


15 kW ECB26−15CB (99M70) 


TABLE 3 


Motor 

Full Load 

Amps 

CB(X)26UH−030 

2 Minimum 

Circuit 

Ampacity 

3 Maximum 

Overcurrent 

Protection 


Circuit 

Ampacity 

Single Point 

Power Source 

3 Maximum 

Overcurrent 

Protection 

208 1.9 6,400 1.6 13.4 − − − 15 − − − − − − − − − 

220 2.1 7,200 1.5 13.8 − − − 15 − − − − − − − − − 

230 2.3 7,800 1.5 14.4 − − − 15 − − − − − − − − − 

240 2.5 8,500 1.5 14.9 − − − 15 − − − − − − − − − 

208 3.8 12,800 1.6 24.8 − − − 4 25 − − − − − − − − − 

220 4.2 14,300 1.5 25.7 − − − 30 − − − − − − − − − 

230 4.6 15,700 1.5 26.9 − − − 30 − − − − − − − − − 

240 5.0 17,100 1.5 27.9 − − − 30 − − − − − − − − − 

208 5.6 19,200 1.6 35.7 − − − 4 40 − − − − − − − − − 

220 6.3 21,500 1.5 37.7 − − − 4 40 − − − − − − − − − 

230 6.9 23,500 1.5 39.4 − − − 4 40 − − − − − − − − − 

240 7.5 25,600 1.5 40.9 − − − 45 − − − − − − − − − 

208 7.5 25,600 1.6 47.1 − − − 4 50 − − − − − − − − − 

220 8.4 28,700 1.5 49.6 − − − 4 50 − − − − − − − − − 

230 9.2 31,400 1.5 51.9 − − − 60 − − − − − − − − − 

240 10.0 34,100 1.5 54.0 − − − 60 − − − − − − − − − 

208 9.4 32,000 1.6 35.8 22.6 4 40 4 25 59 60 

220 10.5 35,800 1.5 37.7 23.9 4 40 4 25 62 70 

230 11.5 39,200 1.5 39.3 24.9 4 40 4 25 65 70 

240 12.5 42,600 1.5 40.9 26.0 45 30 67 70 

208 11.3 38,400 1.6 47.1 22.6 4 50 4 25 70 70 

220 12.6 43,000 1.5 49.8 23.9 4 50 4 25 74 80 

230 13.5 47,000 1.5 51.8 24.9 60 4 25 77 80 

240 15.0 51,200 1.5 54.0 26.0 60 30 80 80 






Page 12

SINGLE PHASE 



















TABLE 4 


Motor 

Full Load 

Amps 

CB(X)26UH−036 / CBX26UH−037 

2 Minimum 

Circuit 

Ampacity 

3 Maximum 

Overcurrent 

Protection 


Circuit 

Ampacity 

Single Point 

Power Source 

3 Maximum 

Overcurrent 

Protection 

208 1.9 6,400 2.1 14.0 − − − 15 − − − − − − − − − 

220 2.1 7,200 2.0 14.4 − − − 15 − − − − − − − − − 

230 2.3 7,800 2.0 15.0 − − − 15 − − − − − − − − − 

240 2.5 8,500 2.0 15.5 − − − 20 − − − − − − − − − 

208 3.8 12,800 2.1 25.5 − − − 30 − − − − − − − − − 

220 4.2 14,300 2.0 26.4 − − − 30 − − − − − − − − − 

230 4.6 15,700 2.0 27.5 − − − 30 − − − − − − − − − 

240 5.0 17,100 2.0 28.5 − − − 30 − − − − − − − − − 

208 5.6 19,200 2.1 36.3 − − − 4 40 − − − − − − − − − 

220 6.3 21,500 2.0 38.3 − − − 4 40 − − − − − − − − − 

230 6.9 23,500 2.0 40.0 − − − 4 40 − − − − − − − − − 

240 7.5 25,600 2.0 41.6 − − − 45 − − − − − − − − − 

208 7.5 25,600 2.1 47.7 − − − 4 50 − − − − − − − − − 

220 8.4 28,700 2.0 50.2 − − − 60 − − − − − − − − − 

230 9.2 31,400 2.0 52.5 − − − 60 − − − − − − − − − 

240 10.0 34,100 2.0 54.6 − − − 60 − − − − − − − − − 

208 9.4 32,000 2.1 36.4 22.6 4 40 30 59 60 

220 10.5 35,800 2.0 38.3 23.9 4 40 30 63 70 

230 11.5 39,200 2.0 39.9 24.9 4 40 30 65 70 

240 12.5 42,600 2.0 41.6 26.0 45 30 68 70 

208 11.3 38,400 2.1 47.8 22.6 4 50 30 71 80 

220 12.6 43,000 2.0 50.5 23.9 60 30 75 80 

230 13.5 47,000 2.0 52.4 24.9 60 30 78 80 

240 15.0 51,200 2.0 54.6 26.0 60 30 81 90 






Page 13

SINGLE PHASE 



















TABLE 5 


Motor 

Full Load 

Amps 

CB(X)26UH−042 

2 Minimum 

Circuit 

Ampacity 

3 Maximum 

Overcurrent 

Protection 


Circuit 

Ampacity 

Single Point 

Power Source 

3 Maximum 

Overcurrent 

Protection 

208 1.9 6,400 2.6 14.7 − − − 15 − − − − − − − − − 

220 2.1 7,200 2.5 15.1 − − − 20 − − − − − − − − − 

230 2.3 7,800 2.5 15.6 − − − 20 − − − − − − − − − 

240 2.5 8,500 2.5 16.1 − − − 20 − − − − − − − − − 

208 3.8 12,800 2.6 26.1 − − − 30 − − − − − − − − − 

220 4.2 14,300 2.5 27.0 − − − 30 − − − − − − − − − 

230 4.6 15,700 2.5 28.1 − − − 30 − − − − − − − − − 

240 5.0 17,100 2.5 29.2 − − − 30 − − − − − − − − − 

208 5.6 19,200 2.6 36.9 − − − 4 40 − − − − − − − − − 

220 6.3 21,500 2.5 38.9 − − − 4 40 − − − − − − − − − 

230 6.9 23,500 2.5 40.6 − − − 45 − − − − − − − − − 

240 7.5 25,600 2.5 42.2 − − − 45 − − − − − − − − − 

208 7.5 25,600 2.6 48.3 − − − 4 50 − − − − − − − − − 

220 8.4 28,700 2.5 50.9 − − − 60 − − − − − − − − − 

230 9.2 31,400 2.5 53.1 − − − 60 − − − − − − − − − 

240 10.0 34,100 2.5 55.2 − − − 60 − − − − − − − − − 

208 9.4 32,000 2.6 37.1 22.6 4 40 4 25 60 60 

220 10.5 35,800 2.5 38.9 23.9 4 40 4 25 63 70 

230 11.5 39,200 2.5 40.5 24.9 45 4 25 66 70 

240 12.5 42,600 2.5 42.2 26.0 45 30 69 70 

208 11.3 38,400 2.6 48.4 22.6 4 50 25 71 80 

220 12.6 43,000 2.5 51.1 23.9 60 4 25 75 80 

230 13.5 47,000 2.5 53.0 24.9 60 4 25 78 80 

240 15.0 51,200 2.5 55.2 26.0 60 30 82 90 






Page 14

SINGLE PHASE 





















TABLE 6 


Motor 

Full Load 

Amps 

(240V) 

CB(X)26UH−048−060 

2 Minimum 

Circuit 

Ampacity 

3 Maximum 

Overcurrent 

Protection 


Circuit 

Ampacity 

Single Point 

Power Source 

3 Maximum 

Overcurrent 

Protection 

208 1.9 6,400 4.1 16.5 − − − 20 − − − − − − − − − 

220 2.1 7,200 3.9 16.8 − − − 20 − − − − − − − − − 

230 2.3 7,800 3.9 17.4 − − − 20 − − − − − − − − − 

240 2.5 8,500 3.9 17.9 − − − 20 − − − − − − − − − 

208 3.8 12,800 4.1 28.0 − − − 30 − − − − − − − − − 

220 4.2 14,300 3.9 28.7 − − − 30 − − − − − − − − − 

230 4.6 15,700 3.9 29.9 − − − 30 − − − − − − − − − 

240 5.0 17,100 3.9 30.9 − − − 4 35 − − − − − − − − − 

208 5.6 19,200 4.1 38.8 − − − 4 40 − − − − − − − − − 

220 6.3 21,500 3.9 40.7 − − − 45 − − − − − − − − − 

230 6.9 23,500 3.9 42.4 − − − 45 − − − − − − − − − 

240 7.5 25,600 3.9 43.9 − − − 45 − − − − − − − − − 

208 7.5 25,600 4.1 50.2 − − − 60 − − − − − − − − − 

220 8.4 28,700 3.9 52.6 − − − 60 − − − − − − − − − 

230 9.2 31,400 3.9 54.9 − − − 60 − − − − − − − − − 

240 10.0 34,100 3.9 57.0 − − − 60 − − − − − − − − − 

208 9.4 32,000 4.1 38.9 22.6 4 40 25 62 70 

220 10.5 35,800 3.9 40.7 23.9 45 25 65 70 

230 11.5 39,200 3.9 42.3 24.9 45 25 68 70 

240 12.5 42,600 3.9 43.9 26.0 45 30 70 70 

208 11.3 38,400 4.1 50.3 22.6 60 25 73 80 

220 12.6 43,000 3.9 52.8 23.9 60 25 77 80 

230 13.5 47,000 3.9 54.8 24.9 60 25 80 80 

240 15.0 51,200 3.9 57.0 26.0 60 30 83 90 

208 15.0 51,200 4.1 50.3 45.1 60 4 50 96 100 

220 16.8 57,300 3.9 52.8 48.0 60 4 50 101 110 

230 18.4 62,700 3.9 54.8 49.9 60 4 50 105 110 

240 20.0 68,200 3.9 57.0 52.1 60 60 110 110 






Page 15

IV−CONFIGURATION MODIFICATIONS 

CB26UH and CBX26UHunits are factory−assembled and 

configured for installation in upflow or horizontal left−hand 

air discharge applications. A kit is available to convert units 

for downflow applications. See OPTIONAL 

ACCESSORIES at the front of this manual. 

If the unit needs to be modified from its original 

configuration, use the following procedures. All procedures 

assume the unit has not been modified from the factory. 

General Information 

WARNING 

Improper installation, adjustment, alteration, service 

or maintenance can cause property damage, personal 

injury or loss of life. Installation and service must 

be performed by a qualified installer or service 

agency. 

Each unit consists of a blower assembly, refrigerant coil, 

and controls, in an insulated galvanized steel factory 

finished enclosure. Knockouts are provided for electrical 

wiring entrance. 

For ease in installation, it is best to make any necessary coil 

configuration changes before setting air handler in place. 

If a filter is to be installed at the air handler, a filter rack must 

be formed using factory−supplied flanges. Lay the unit on its 

back and pry out the filter rack tabs as shown in figure 5. 

Filter Rack Tabs 

4. Install units that have no return air plenum on a stand 

that is at least 14" from the floor. This will allow proper 

air return. 

HORIZONTAL 

DRAIN PAN 

(Remove for best 

upflow performance) 

Upflow Configuration 

UPFLOW 

DRAIN PAN 

UPFLOW DRAIN 

CONNECTIONS 

(Both sides; use 

on side or other) 

FIGURE 6 

HORIZONTAL 

DRAIN 

CONNECTIONS 

(Both sides; Not 

used) 

Horizontal Applications 

NOTE − When the unit is installed in horizontal applications, 

a secondary drain pan is recommended. Refer to local 

codes. 

This unit may be installed in left−hand or right−hand air 

discharge horizontal applications. Adequate support must 

be provided to ensure cabinet integrity. Ensure that there is 

adequate room to remove service and access panels if 

installing in the horizontal position. 

1. Determine whether left-hand or right-hand air 

discharge is required. If right-hand is required, perform 

Right−Hand Discharge Modification. See next page. 

2. Determine knockouts required for drain line 

connections. 

3. With access door removed, knock out drain line 

opening for installing drain lines. 

4. Set unit so that it is sloped (up to 1/4 inch) toward the 

drain pan end of the unit. 

5. The horizontal configuration is shown in figure 7. 

Left−Hand Air Discharge Configuration 

FIGURE 5 

AIR 

FLOW 

Drains 

Upflow Application 

1. The air handler must be supported on the bottom only 

and set on solid floor or field-supplied support frame. 

Securely attach the air handler to the floor or support 

frame. 

2. If installing a unit in an upflow application, remove the 

horizontal drain pan; it is not required in upflow air 

discharge installations. 

3. Place the unit in desired location. Set unit so that it is 

level. Connect return and supply air plenums as 

required using sheet metal screws. 

KNOCKOUT 

FIGURE 7 

LEFT-HAND DRAINS 

6. If the unit is suspended, the entire length of the cabinet 

must be supported. If you use a chain or strap, use a 

piece of angle iron or sheet metal attached to the unit 

(either above or below) to support the length of the 

cabinet. Use securing screws no longer than 1/2 inch 

to avoid damaging the coil or filter. See figure 8. Use 

sheet metal screws to connect the return and supply air 

plenums as required. 

Page 16

Suspending Horizontal Unit 

ANGLE IRON OR 

SHEET METAL 

1/2 in. Screws max. 

AIR 

FLOW 

FRONT VIEW 

FIGURE 8 

IMPORTANT 

Electrical Inlet Clearance 

4 in. (102 mm) 

END VIEW 

When removing the coil, there is possible danger of 

equipment damage and personal injury. Be careful 

when removing the coil assembly from a unit 

installed in right− or left−hand applications. The coil 

may tip into the drain pan once it is clear of the cabinet. 

Support the coil when removing it. 

Right−Hand Air Discharge Modification 

Right−Hand Air Discharge Configuration 

Drains 

AIR 

FLOW 

Field Modification for Right−Hand Discharge 

REMOVE 

DRAIN PAN 

FROM HERE 

THEN... 

DETAIL A 

REINSTALL 

PAN HERE 

REMOVE 2 

SCREWS AND 

BP BRACKET 

FROM HERE 

THEN... 

ROTATE BP 

BRACKET AND 

REINSTALL 

REMOVE 

COIL SUPPORT 

BRACKET 

FROM HERE 

THEN... 

REINSTALL 

BRACKET 

HERE 

BRACKET 

SHOWN AS 

SHIPPED 

BRACKET 

SHOWN FOR 

RIGHT HAND 

DISCHARGE 

DETAIL B 

FIGURE 10 

Right-Hand Discharge Drain Plug Location 

KNOCKOUT 

RIGHT-HAND DRAINS 

FIGURE 9 

For horizontal right−hand air discharge, the following field 

modifications are required. 

1. Remove and set aside blower and coil access covers. 

2. Remove the coil support bracket (see detail A, figure 

10). 

3. Remove coil assembly, bottom drain pan and 

horizontal drain pan as one assembly from the air 

handler. 

4. Remove the drain plugs from back of horizontal drain 

pan and reinstall in the front holes. 

5. Remove two screws and blowoff prevention bracket 

(BP BRACKET in figure 10). Rotate the bracket 180º 

and reinstall using the same screws. 

6. Move horizontal drain pan to the opposite side of the 

coil. Plugged drain holes will now be toward the back 

of the unit (see figure 11). 

7. Re−install modified coil/drain pan assembly in air 

handler in the same orientation as before. 

8. Install the coil support bracket on the opposite side of 

the air handler (detail B, figure 10).. 

ORIGINAL 

PLUG 

LOCATION 

NEW PLUG 

LOCATION 

COIL 

ASSEMBLY 

FIGURE 11 

PLUGGED 

END 

OPEN END FOR 

CONDENSATION 

DRAIN 

Install Condensate Drain 

The air handler is provided with ¾" NPT condensate drain 

connections. 

IMPORTANT 

A field−fabricated secondary drain pan, with a drain 

pipe to the outside of the building, is required in all 

installations over a finished living space or in any 

area that may be damaged by overflow from the main 

drain pan. In some localities, local codes may require 

an secondary drain pan for any horizontal installation. 

Page 17

Make sure the unit is sloped (up to 1/4 inch) so that the drain 

pan will empty completely without water standing in the 

pan. See figure 12. 

THIS CORNER 

SHOULD BE 

5/8 (+/− 1/8) 

HIGHER THAN 

DRAIN CORNER 

DRAIN CORNER 

FIGURE 12 

THIS CORNER 

SHOULD BE 

5/8 (+/− 1/8) 

HIGHER THAN 

DRAIN CORNER 

1. Remove the appropriate drain knockouts. If necessary, 

remove the indoor coil assembly from the cabinet. 

2. Connect primary drain line connection to the primary 

drain pan connection. The primary drain connection is 

flush with the bottom of the inside of the pan. 

Secondary connection is raised above the bottom of 

the inside of the pan. 

NOTE − When making drain fitting connections to the drain 

pan, hand tighten the fitting and use a sealant. 

Overtightening the fittings can split connections on the 

drain pan. 

3. Secondary drain connections, if used, should be 

connected to a separate drainage system. Run the 

secondary drain line to a place where the occupant 

would be sure to notice any drainage from the drain. 

4. Install a 3" trap in both the primary and secondary drain 

lines as close to the unit as practical (see figure 13). 

Make sure the top of the trap is below the connection 

to the drain pan to allow complete drainage of the pan. 

Typical Condensate Drain Connection 

(Secondary Drain Not Shown) 

AIR 

HANDLER 

DRAIN PAN 

DRAIN CONNECTION 

ANTI−SIPHON 

DRAIN LINE AIR VENT 

12" Max. 

DRAIN TRAP 

FIGURE 13 

1" Min. 

3" Min. 

NOTE − Horizontal runs over 15 ft. long must also have an 

antisiphon air vent (standpipe) installed ahead of the 

horizontal run (See figure 13). An extremely long horizontal 

run may require an oversized drain line to eliminate air 

trapping. 

NOTE − Do not operate air handler without a drain trap. The 

condensate drain is on the negative pressure side of the 

blower; therefore, air being pulled through the condensate 

line will prevent positive drainage without a proper trap. 

5. Route the drain line to the outside or to an appropriate 

drain. Drain lines must be installed so they do not block 

service access to the front of the air handler. A 24" 

clearance is required for filter, coil, or blower removal 

and service access. 

NOTE − Check local codes before connecting the drain line 

to an existing drainage system. 

6. Insulate the drain lines where sweating could cause 

water damage. 

Test Condensate Drain 

Test the drain pan and drain line after installation: 

1. Pour several quarts of water into drain pan, enough to 

fill drain trap and line. 

2. Check to make sure the drain pan is draining 

completely, no leaks are found in drain line fittings, and 

water is draining from the end of the primary drain line. 

3. Correct any leaks found. 

V−START-UP − OPERATION 

A−Preliminary and Seasonal Checks 

1− Make sure the unit is installed in accordance with the 

installation instructions. 

2− Inspect electrical wiring, both field and factory installed for 

loose connections. Tighten as required. 

3− Check voltage at disconnect switch. Voltage must be 

within range listed on the nameplate. If not, consult the 

power company and have voltage condition 

corrected before starting unit. 

4− Check to ensure that refrigerant lines are in good 

condition and pipe insulation is intact. 

5− Inspect condition of condensate drain pan and piping 

assembly. Disassemble and clean seasonally. 

B−Cooling Start-Up 

NOTE−The following is a generalized procedure and 

does not apply to all thermostat control systems. Electronic 

thermostat control systems may operate differently. 

1− Set fan switch to AUTO or ON and move the system 

selection switch to COOL. Adjust the thermostat to a 

setting far enough below room temperature to bring on 

the compressor. Compressor will start and cycle on 

demand from the thermostat. After a 30 second time 

delay (approximate) the indoor blower will energize. 

2− The refrigerant circuit is charged with HCFC−22 or 

HFC−410A refrigerant. See condensing unit rating 

plate for correct charge amount. 

3− Refer to the correct condensing unit service manual for 

more information. 

C−Heating Start-Up 

1− Set the fan switch to AUTO or ON and move the 

system selection switch to HEAT. Adjust the 

thermostat setting above room temperature. 

2− The indoor blower and the electric heat will stage on based 

on sequencer timing. 

D−Safety or Emergency Shutdown 

Turn off unit power at circuit breaker. 

E−Extended Period Shutdown 

Turn off thermostat or set to UNOCCUPIED mode. Turn off 

power to unit. All access panels and covers must be in place 

Page 18

and secured. The condensate assembly should be clean 

and dry for extended period shutdown. 

VI−TYPICAL OPERATING CHARACTERISTICS 

A−Blower Operation and Adjustment 

NOTE− The following is a generalized procedure and 

does not apply to all thermostat controls. 

1− Blower operation is dependent on thermostat 

control system. 

2− Generally, blower operation is set at thermostat 

subbase fan switch. With fan switch in ON position, 

blower operates continuously. With fan switch in AUTO 

position, blower cycles with demand. 

3− In all cases, blower and entire unit will be off when the 

system switch is in OFF position. 

B−External Static Pressure 

1− Measure tap locations as shown in figure 14. 

SUPPLY 

STATIC PRESSURE TEST 

MANOMETER 

FIGURE 14 

RETURN 

UNIT SHOWN IN 

HORIZONTAL DISCHARGE LEFT POSITION 

2− Punch a 1/4" (6mm) diameter hole in supply and return 

air plenums. Insert manometer hose flush with inside 

edge of hole or insulation. Seal around the hose with 

permagum. Connect the zero end of the manometer to 

the discharge (supply) side of the system. On ducted 

systems, connect the other end of manometer to the 

return duct as above. For systems with non−ducted 

returns, leave the other end of the manometer open to 

the atmosphere. 

3− With only the blower motor running and the 

evaporator coil dry, observe the manometer 

reading. Adjust blower motor speed to deliver the air 

desired according to the job requirements. 

4− For best air performance external static pressure 

drop must not exceed 0.5" W.C. (1.2 kPa). Refer to 

blower data tables for cfm and external static. 

5− Seal around the hole when the check is complete. 

C−Blower Speed Taps 

Change Blower Speed 

WARNING 

Electric shock hazard! − Disconnect all 

power supplies before servicing. 

Replace all parts and panels before 

operating. 

Failure to do so can result in death or 

electrical shock. 

1. Disconnect all power supplies. 

2. Remove the air handler access panel. 

3. Locate pin number 2 on the blower relay. Two black 

wires are connected to this terminal pin. One connects 

to pin number 5 on the blower relay, one connects to an 

inline splice connecting to a red or blue wire. 

4. Remove the wire going to the 4−pin blower motor 

connector from the splice. 

5. Connect the blower lead [Red (LO), Black (HI)] onto the 

splice from the 4−pin blower motor connector. 

NOTE − Unused blower speed taps are factory−covered 

with plastic caps. Remove this cap from the desired blower 

speed tap and replace it over the factory−set blower tap. 

6. Replace all panels. 

7. Reconnect power. 

VII−MAINTENANCE 

WARNING 

Disconnect power before performing any 

maintenance. 

At the beginning of each heating/cooling season, the 

system should be checked as follows: 

A−Filters 

NOTE− Filter access panel must be in place during unit 

operation, or excessive warm air may enter the unit 

resulting in water blow−off problems. 

TABLE 7 

Unit Air Filter Size Chart 

Model 

Filter Size 

18 / 24 16" x 20" 

30 / 36 18" x 20" 

42 / 48 / 60 18" x 25" 

To remove filter, remove 1/4" head screws holding the 

filter panel in place. Slide filter out of the guides on either 

side of cabinet, insert new filter and replace panel. 

Filters should be inspected monthly and must be 

replaced when dirty to ensure proper blower coil 

operation. See table 7 for replacement filter sizes. 

B−Supply Air Blower 

1- Check and clean blower wheel. 

2- Motors are prelubricated for extended life; no further 

lubrication is required. 

C−Electrical 

1- Check all wiring for loose connections. 

2- Check circuit breaker located in unit control box. 

3- Check for correct voltage at unit (unit operating). 

4- Check amp-draw on blower motor. 

5- Check to see that heat (if applicable) is operating. 

Page 19

VIII−WIRING DIAGRAMS AND SEQUENCE OF OPERATIONS 

220 

208/240 

VOLTAGE 

BY 

OTHERS 

CIRCUIT BREAKER 2 (OPT) 

L1B 

L2B 

GND 

CIRCUIT BREAKER 1 (OPT) 

L1A 

L2A 

12 BK 

12 BK 

12 BK 

12 BK 

18 BU 

SEQUENCER 2 

5 4 

3 1 

12 Y 

12 Y 

SEQUENCER 1 

5 4 

3 1 

18 BK 

12 BK 

12 BK 

3 

6 

ELECTRIC HEAT − 2ND STAGE 

LIMIT SWITCH 3 


HE4 

7 

HE3 

ELECTRIC HEAT − 1ST STAGE 


12 BK 

4 

12 BK 

12 Y 


HE2 

HE1 

14 BK 

14 BK L1 

GND 

TO BLOWER 

GROUND LUG 

6−PIN 

1 2 3 4 PLUG 5 6 

1 2 3 4 5 6 

COM 

14 Y 

14 Y L2 

208V 

240V 

1 

TRANSFORMER 

24 

24V 

C 

14 G 

18 R 

18 BU 

14 R 

18 BU 

H 

12 Y 

H 

18 W 

8 

3 

18 BK 

6 

18 BK 

18 W 

18 BU 

18 G 

18 R 

POWER (FACTORY WIRED) 

POWER (FIELD WIRED) 

CONTROL (FACTORY WIRED) 

CONTROL (FIELD WIRED) 

CONTROL CIRCUIT WIRING TO BE 24 VOLT, N.E.C. CLASS 2 

W2 

W1 

C 

G 

R 

BK 

W 

BU 

G 

R 

TO THERMOSTAT 

2 

1 2 3 

4 5 6 

6−PIN 

PLUG 

HEATER ELEMENTS USED: 

5KW − HE1 

7.5 & 10KW − HE1 & HE2 

15KW − HE1, HE2, & HE3 

20KW − HE1, HE2, HE3, & HE4 

14 BK 

18 BU 

14 R 

3 

6 

18 BU 

18 G 

4 

BLOWER 

RELAY 

TIME DELAY 

H =10 TO 60 SECONDS TO HEAT UP 

C =10 TO 60 SECONDS TO COOL DOWN 

1 

5 

5 

2 

14 R (LO) 

9 14 BK (HI) 

14 Y (COM) 

4 

3 

2 

1 

BR/W 

R 

BLOWER 

BK MOTOR 

Y+ BR MOTOR 

CAPACITOR 

Figure 15. Wiring Diagram CB(X)26UH−0XX−(R)−230−01 and CB(X)26UH−0XX−(R)−230−02 Builds 

Page 20

WARNING 

USE COPPER 

CONDUCTORS 

ONLY 

Figure 16. Wiring Diagram Applicable to units with a three speed motor with date of manufacture date code of January 

2009 through January 2010: 

Page 21

A−ECB26UH & ECBX26UH − SEQUENCE OF OPERATION 

FIRST STAGE HEAT 

1− Line voltage is routed to transformer and blower 

relay. 

2− 24VAC is supplied to indoor thermostat and electric 

heat, if used. 

COOLING 

3− When there is a call for heat W1 of the thermostat 

energizes sequencer relay 1. 

8− 

4− Assuming limit switch 1 and 2 are closed, sequencer 

relay 1 energizes HE1 and HE2. 

9− 

5− Indoor blower is energized on heating speed, after 

sequencer timing is complete. 

SECOND STAGE HEAT 

6− W2 in the thermostat energizes sequencer relay 2. 

7− Assuming limit switch 3 and 4 are closed sequencer 

relay energizes HE3 and HE4. 

When there is a call for cooling, G of the thermostat 

energizes blower time delay relay. 

After a 30 second delay (approximate) blower relay 

energizes blower motor on cooling speed. Blower will also 

delay 30 seconds after cool demand is satisfied. 

Page 22

CB26 - Heating and Air Parts

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